


Unforeseen Fate

by BWolf_20



Category: The Avengers (Marvel Movies)
Genre: Avengers: Infinity War Part 1 (Movie) Spoilers, Bathing/Washing, Captivity, Eventual compliant Tony Stark, Force-Feeding, Gen, Guilt, Hurt Tony Stark, Loss of Humanity, Master/Pet, Non-Consensual Body Modification, Non-Consensual Spanking, Non-Sexual Spanking, Non-con situation, Nudity, Pet Tony Stark, Survivor Guilt, Taking creative liberties with Thanos and any alien planet, Thanos Wins, Thanos takes good care of his pet, no real happy ending, tail
Language: English
Status: Completed
Published: 2018-10-05
Updated: 2018-10-18
Packaged: 2019-07-25 11:35:57
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 8,300
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16196738
Author URL: https://archiveofourown.org/users/BWolf_20/pseuds/BWolf_20
Summary: Tony can only mourn now that Thanos has won against humanity. In his mind it would have been better if he had become dust in the wind along with the others, but Thanos returns and carries him away. He can barely put up a struggle to fight for his life. To his surprise, Thanos doesn’t kill him. Instead he takes care of him as he intends for Tony to keep him company as his new pet.





	1. Chapter 1

**Author's Note:**

> I recently saw 'Avengers: Infinity War' and I enjoyed it a lot :D. I didn't expect I would since I didn't take to the sequel 'Age of Ultron' and the Infinity trailer didn't excite me. Of course it's fun giving Tony a hard time in fanfics, and now there's the added bonus of including Thanos.  
> I'm pretty intrigued to see some Infinity fics, and this idea was on the top of my mind, but my inspiration mainly came from reading a few Tony/Thanos fics.

Tony had no concept of how long he sat there with his eyes closed and his hands pressed tight against his mouth. In truth he did not care. There was little to nothing left to care about now that he was alone. The newcomer, the blue-toned woman, did not count. He was alone. The crew that he had just met had vanished. Dr. Strange, a new acquaintance, had disappeared as well. And Peter…a kid that was making his way closer into his heart had tapped out of existence as well. He had not wanted to go. Of all people, Tony did not want the kid to go, and no matter how hard he had clung to him, he had gone anyway. The image of his face literally disintegrating would be forever etched into his mind.

His hands started to tremble. He moved his hands away as he dropped his head against them, looking as though he was praying. Tears didn’t slip from his eyes, but a choke escaped his lips as the loss intensified.

“We should go,” came the woman’s voice.

Tony didn’t acknowledge the suggestion. Where was there to go after this? Thanos had won. He would have this pain no matter where he went now. If he went back home, it would only worsen, maybe even kill him. 

But when he thought of home, he thought of Pepper, and in turn he wondered if she had suffered the same fate of falling out of existence.

“No,” he muttered shakily. He wouldn’t believe she was gone. She would still be there, waiting to curse him, then embrace him. He would return to earth to make sure this happened, but he was too scared to move. He was too scared to go and find out that it wouldn’t be true. What if she wasn’t there? What if she had gone just like Peter? His heart couldn’t take it.

“We have to go,” came the woman’s voice again. Clearly she had thought Tony’s “No” was a refusal to leave. In a way, it was.

He opened his eyes which had become red, and looked at her. Why couldn’t she see that he wasn’t really there? That there was nothing left of him except a shell of a man. What good would it do for him to leave? What good could he do for anyone at the moment? Why did he deserve to leave and return to some form of life when the others couldn’t?

The mysterious woman said nothing more. Perhaps at last she saw all of those questions as she looked at him.

Then behind her, the space came apart as a purplish portal opened. Out of that portal came the last thing he wanted to see. 

Thanos wasn’t smiling as he walked through, but when he came to a stop and stared at Tony, the corners of his lips lifted.

“Stark, I’m glad to see you’ve waited for me.”

Tony wanted to inform him that he wasn’t waiting for him, but no words came out. He simply sat like a zombie, somehow feeling more defeated at his presence. The woman reacted quickly as she sprung to attack. It was useless of course as he easily knocked her aside with a vicious strike to her abdomen. His attention was solely on Tony as he moved forward.

He made no attempt to summon his suit since it was already badly damaged. In fact he made no move to do anything except watch his executioner come forward. He welcomed it. He hadn’t been able to protect the kid or ensure earth’s safety, so of course he deserved the same fate as the others. If anything it would be a way for him to escape the dark hollowness that was consuming him. 

Thanos came to a stop right before him, and his smile widened just slightly.

“Nothing to say? No annoying little quip? No fiery blast from your suit?”

Tony dropped his head. What could he say now after everything? It was too soon for any of that.

“I understand,” Thanos continued. “I understand the grief you feel, because I feel it too.”

“Bastard,” Tony whispered venomously. “You have no…idea…you…”

“I do.”

Tony lifted his eyes and saw the now damaged looking gauntlet. A fire suddenly lit and he sprung to his feet as he pulled his arm back to deliver a punch. His fist was immediately engulfed in Thanos’s much larger hand.

“Now is not the time for fighting Stark. Now is the time, for healing.”

He wouldn’t hear such lies. Despite how pathetic it was, he pounded against the giant’s arm with his free hand. All the anger, all the sadness, was wrapped up in those punches. He was barely aware of how wet his eyes had become. 

The smile dropped from Thanos’s face as he grabbed his other hand, stopping the assault.

“Enough of this Tony. What good would it do? Your power is gone. Your friends, all of your friends, are nothing but dust.” 

Tony stopped struggling then as he stared into his eyes. The fire was extinguished. His head dropped, and he slumped. If Thanos hadn’t been holding onto his hands, he would have dropped to the ground.

“You’re alone, but not for long.”

Tony didn’t have the energy to question what he meant. He had no energy or fight left as Thanos maneuvered him closer to himself. He released a hand which dropped to Tony’s side, and after that his large fingers reached for his hoodie. Tony made no effort to stop him as he pulled an arm free of the sleeve, then did the same to the other. He was as limp as a doll, yet steady on his feet as the titan went through the odd process of undressing him.

Once he was rendered completely shirtless, Tony bothered to ask.

“What are you doing?”

He wouldn’t even look at Thanos. He couldn’t bear to be reminded of the horrible defeat. Thanos wouldn’t answer even as he started working his pants down his legs. He grabbed onto his underwear and ripped them from his form, causing Tony to grunt from the force of it. And now he stood, naked on a foreign planet, before the creature that had destroyed so much. He felt the heat rising in his cheeks as he gave the titan a questioning look. His lip trembled as he smiled softly at him. Was this all just to humiliate him? Was it some insinuation that he was not a man because he had failed so hard?

One of Thanos’s large hands cupped the back of his head. His fingers disturbed his hair in a near soothing manner. Tony simply stared back at the titan, not knowing what to do.

“Fight back!”

He turned his gaze to the woman. She was lying flat on her stomach, seeming to struggle to rise. It was clear from the pain in her face that the strike from Thanos had done some horrible damage to her body. But rather than show fear, she showed determination as she stared Tony in the eyes.

“Fight back!” she encouraged. She was desperate for the beast to get what he deserved. 

Tony heard the words, but they meant nothing. He couldn’t feel anything at the moment, let alone the desire to fight any longer. Thanos shifted his gauntlet covered hand down under his bare ass and lifted him into his arms. Tony shifted from the uncomfortable feeling of the metal as he was cradled like a newborn babe. Thanos smiled down at him and ran his fingers over his hair. Tony was quite numb to what was happening. He stared into that big face, not understanding why this was happening. Why would he have to die in such a humiliating way?

Thanos started moving and a portal appeared in front of him. Tony turned to it, imagining that he was about to be returned to earth to face the rest of the devastation, in his sad state. What did it matter now? Everyone was gone.

“No. No!” the woman cried.

Thanos ignored her as he stepped through the portal, leaving her and Tony’s clothes behind him.


	2. Chapter 2

The place Tony saw definitely wasn’t earth, but it was lush and a more beautiful sight than Titan. It was a feast of greens and unusual colors. The air seemed richer as it invaded Tony’s lungs, but despite the new environment, his feelings didn’t change. He was so empty, he could barely hold onto the embarrassment he felt as Thanos continued to carry his naked body in his arms. It was only now that the feeling of the bare arms registered against his bare skin. He shifted a little in a useless attempt to create some distance, but there was no escaping the feeling of skin on skin. If anything, he felt his palm better against his ass cheeks.

“The hell are we?” he asked in an attempt to try and distract himself.

“Your new home, with me.”

A twinge of dread filled his heart with the notion that he would never see his real home again. Then again, he wasn’t sure he could even face a trip back home. He could only make it if he knew for certain that he hadn’t lost everybody; that Pepper and Rhodes and Bruce, and even the rest of the team were still alive.

Tony looked up into Thanos’s face. He had suggested all his friends were gone, but was it true?

Thanos carried him to an area of marble arches and pathways that almost mimicked Roman architecture with rising columns. He followed a path past a garden and over to a large, beautiful, rocky pool, complete with a small waterfall. Tony looked down at his reflection in the water. He looked so worn, so broken. Thanos shifted Tony to where he was holding him under his arms as a parent might do with a small child. As he was lowered toward the water, panic set in, causing Tony to put up a struggle once more. He would not let Thanos drown him if he could help it.

“Settle down Tony. Your filth needs to be dealt with.”

“No…no!” 

“Don’t be ridiculous.”

No amount of kicking saved his feet from dipping into the water which was pleasantly lukewarm. Thanos continued to lower him down until his bottom hit the floor with the water coming up to his chest. He next took a moment to remove the battered gauntlet which momentarily caught Tony’s attention. He couldn’t help feeling how pointless it was to see it off now after all the trouble he and the others had gone through to take it. The damage was done. 

Thanos turned to Tony and brought down a hand to hold him in place, causing him to fight tooth and nail. He couldn’t make sense of what was happening. Surely his enemy wasn’t about to give him a bath. But it appeared to be the case as he next felt a soft cloth rubbing across his face. He cried his displeasure, but his words were muffled. After his face was nicely cleaned, Thanos rubbed it against his left-hand side. Tony stopped struggling as he leaned forward, panting and groaning in frustration. Thanos paid it no mind as he gently rubbed the cloth up and down.

“There now, not so bad right?” 

Tony hated the tone he was using. It was like he was pacifying a child. He was a man for god’s sake, yet he felt far from it. The small amount of fight he had summoned to struggle against him just then was gone. He slumped and let his arms drop to his side. Thanos was stronger and he was without his suit which wasn’t working anyway. What chance did he have of fighting, less he wanted to piss him off? 

He wanted to piss him off, but as Thanos moved the cloth along his back, that desire evaporated and was replaced by the great sense of loss. He shut his eyes, willing the tears back as he saw again faces crumbling into dust. The titan lifted the cloth and let the water cascade down his back. Tony gave a slight moan as the feeling was somewhat soothing. It was the thing needed in such a situation. Had he been able to return home, he imagined he would have locked himself in his bathroom and stayed under the shower for a couple of hours. Maybe even the whole day. 

Thanos smiled at the docile human. He could see little tremors wracking his body, but he was sure he’d calm soon enough. He dipped the cloth to get a good soak, then positioned it over his head, letting the water rain over his scalp and face. Tony’s mouth parted just slightly. That did feel good, and part of him was sickened for liking it. This beast had killed half the world! He had killed his friends! He had killed an innocent kid! And yet he was enjoying getting bathed by their murderer.

He felt the cloth on his back once more, moving up and down to wipe away the sweat. 

“Your body must be aching after the fight you put up.” Tony wished they could’ve just stayed in the silence of the moment. “But, I’ll have you cleaned in no time.”

He reached for his right arm and raised it out of the water so it could be cleaned. Tony allowed him to do it. 

“Why?” he decided to ask.

“Well that’s a loaded question,” Thanos said with a slight chuckle.

Tony gritted his teeth as a small wave of anger took him, but then it was gone.

“Why are you doing this? You think…you think a goddamn bath is going to make me feel better about what you did?”

“It might. But I’m doing this because you’re dirty. Because you’re mine now.”

Tony opened his eyes. 

“What do you mean yours?” Thanos dropped his arm in favor of cleaning the other one. The cloth moving over his sore muscles made him tingle. Thanos wouldn’t say. He just smiled at him as if he knew some juicy secret. “You don’t, need me. I can’t do anything for you. You’ve won, Jesus you’ve won! Just let me go home.”

“There’s no need for you to go home Tony. There’s nothing and no one for you there.”

Once again he was reminded of the idea that everyone he knew and cared for might have bit the dust. He wondered if he knew if Pepper had suffered the same fate. That in turn had his heart pounding painfully in his chest.

“Tell me…are they…are they, all gone?” he asked in a shaky voice. He felt his eyes getting wet. Thanos turned him so he could start cleaning his chest. “Pepper, is she…gone too?”

Thanos stopped cleaning and observed Tony who stared pleadingly into his eyes.

“I did not stick around to see how many of your friends survived, but I can assure you the Avengers are finished. Your time with this Pepper person, is no more. Who would have you now Tony? Tell me. You and I went head to head, yet you couldn’t even kill me. If I were you, I wouldn’t show my face.”

It was a slap to the face. Guilt was rising from the pit of his stomach and threatened to make him vomit. Yes, he’d had Thanos one on one, yet he had not been powerful enough or clever enough to take him out. He had designed this amazing Nano tech, but it had not been good enough to spare the world this pain. 

He shut his eyes as the titan moved the cloth farther down to reach his stomach. He thought about what Strange had said. He had foreseen one possibility where they could win. Had he seen wrong? Had he not foreseen his loss against Thanos? Perhaps he saw the rest of the team taking Thanos out after he had taken the time stone, but clearly they had failed as well. Earth’s mightiest heroes hadn’t been mighty enough.

“Rise. I need to clean below.”

He didn’t wait for Tony to comply as he lifted him to his feet with one arm. Tony’s head hung as sobs left his throat. Slowly the cloth was moved down his thigh. It wasn’t until he moved inward did he freak out. 

“No! NO! Get your goddamn paws off me!”

“Tony,” he admonished.

“Let me go damn it! LET ME GO!”

He’d had enough. He was crazy for even finding the bath relaxing. It was madness when he should be sucking up the pain and finding a way out. Again he punched the huge hand that held him, but it didn’t faze Thanos one bit. He set the cloth down and sat at the pool’s edge. In one quick movement, he pulled Tony from the water and laid him stomach side down across his lap. One arm fell across his back, preventing Tony from rising, while the other arm reeled back so as to deliver a hell of a smack against Tony’s bare ass. Tony yelped in surprise. He put up more of a tantrum with kicking legs and pounding fists that struck Thanos’s thigh.

“Unless you behave yourself, this is what you can expect as a punishment.”

The hand came down again, jiggling his cheeks with an amazing force that had him howling. His mind couldn’t comprehend that this was actually happening. Thanos repeated the action, bringing his hand down quicker in a steady pattern of repeated smacks.

_SMACK…SMACK…SMACK…SMACK…SMACK…SMACK_

“STOP! Stop…what the hell…you can’t…”

“Are you going to behave?”

He never stopped. The smacks continued and his bottom was quickly becoming red. Tony stopped pounding against his thigh and just tried to wiggle out from underneath him, but Thanos’s kept him all but immobile. 

_SMACK…SMACK…SMACK…SMACK_

The pain was quickly overtaking anything else Tony was feeling as his cheeks were burning. He was sure if he kept it up, he might actually start bleeding down there.

“Are you going to behave, or must I continue?”

The tears were rising from Tony’s eyes, and as he choked they ran down his face. 

“Please.” He dropped his head as the pain was mixed with an intense shame. Thanos smacking his ass couldn’t have been more mortifying. “Please.”

“Are you going to behave?”

Tony released a shuttered breath as the tears flowed quickly.

“Yes!” he cried in a broken voice. “Yes.”

Thanos smiled and stopped. The last thing Tony wanted to do was cry in front of this mad alien, but it was happening anyway. He sniffled as he laid limp across his lap. The agony brought more tears to his eyes, and that combined with the shock and shame had him shaking.

“I didn’t want to have to do that, but I did it for your own good,” Thanos admitted softly. He gently rested his fingers on his cheeks, making Tony jerk. He thought he might spank him again, but instead he started rubbing circles into the flesh, gently. “You are mine now, which means you must behave and do as you’re told. In the long run it keeps you safe, and good. You want to be good for me, don’t you pet?”

Without thinking, Tony nodded.

“I can’t hear you pet.” Thanos deepened his rubs against his cheeks, even going as far as to knead them. Tony felt a jolt from the feeling. 

“Yes.”

“Very good Tony.” 

The massaging of his bottom continued, despite the fact that it was still stinging. Tony moaned softly and stared at the ground past watery eyes. He couldn’t understand how he had fallen into such a humiliating situation.

“Alright,” said Thanos after a moment. He raised Tony up and dipped his body back into the pool. “Stand for me so I can clean the rest of you. And this time, no fighting.”

Tony didn’t fight this time. He remained perfectly compliant as Thanos started cleaning him with the cloth again. As he went over his backside, Tony tensed. Thanos shot him a warning look as he proceeded to clean his cheeks in a circular motion.

“I can do that myself,” Tony declared.

“From now on, I see to your needs.”

This time when he moved inward in the front, Tony didn’t jerk away. He forced himself to let Thanos clean his privates, curling his toes tightly as he did so. All the while, Tony couldn’t help worrying that those large fingers would break something, but they never did. 

“There now. Much more appropriate,” Thanos noted as he pulled the cloth away.

Tony released a shaky breath of relief now that it was over, but what scared him now was what came next. He barely had a chance to wonder as he was suddenly lifted from the pool. The titan revealed a fluffy towel which he used to dry him. Tony felt like he was barely aware of it as he stared numbly back at the titan while his mind struggled to process what was happening.

Thanos smiled as he turned him for a final inspection. Once satisfied, he threw the towel aside and clapped him on the shoulders.

“I’m sure you’ve worked up an appetite. Come, pet.”

Without bothering to ask for permission, he scooped Tony up and rested him against his massive chest. Tony fell against it like a baby as the arms secured him under his bottom and over his back. He didn’t question where they were going next or what he had planned for the menu. Instead his thoughts focused on the new term, 'pet', which filled his heart with even more dread.

**Notes for the Chapter:**

> Thanos making sure his pet is nice and clean ;)  
> Poor Tony though. His treatment is just going to get more bizarre and dehumanizing.


	3. Chapter 3

When Tony was able to clear away some of the shock from what had just happened, he lifted his head away from his shoulder and noticed that Thanos had brought him into what looked like an ancient throne room, complete with a marble throne. Vines crept up the columns and even hung through openings in the broken ceiling. 

“Like it?” Thanos asked when he noticed Tony taking it in. He removed the hand he hand on his back and ran it down the back of his head as if he was petting him. After a few strokes, Tony batted his hand away.

“Stop it!” His mind focused back to his new title of ‘pet’. “I’m not an animal, and I’m sure as hell not your pet.”

“In time you’ll feel differently,” Thanos countered. “Face it Tony, there’s no going back, not to your old life anyway. It’s time to embrace a new one.”

“Fuck you!”

He went back into attack mode, punching and clawing into that hardened flesh.

“You should save your energy, or are you trying to annoy me to the point where I have to deliver another punishment?”

The threat had done the trick, and Tony stilled. It was hard to believe he was that defeated. Physically fighting him was as useless as it had been with the suit, but now it warranted a more disturbing retaliation from his enemy.

“Just do it already,” he said tiredly, “kill me.”

“You think I would go to all this trouble just to end your life? What would be the point?”

“Nothing you’ve done has any point. Killing half the world’s population doesn’t make things better. Killing Strange, and Peter…” He paused as he saw the boy’s bright eyes turn into the dull color of dirt before vanishing. He balled his fingers into a fist as he willed himself not to think about it now. “What you’ve done, doesn’t save anyone.”

He stared the monster in the eyes, hoping everything he was feeling was driven home into his core. Any normal antagonist of his would have returned that look to a degree, but it was different here. He recalled that Mantis girl of Quill’s stating that Thanos was mourning, and somehow he could see it clearly in his eyes. It wasn’t an act. He really had some feeling of sorrow.

With his focus on his eyes, Tony failed to see the cage behind him. He only became aware of it as Thanos deposited him into it with a light plop. Before Tony could really react, the top was closed down over him and locked. 

“What the hell! Let me out of here!” 

He grabbed onto the rough dirt like bars. Unlike the fancy décor of the marble, the cage seemed to be made entirely out of dirt. It gave the impression that he could easily break the thin bars, but they were as hard as stone.

“Asshole.”

“Stop struggling Tony. You’ll only hurt yourself. And speaking of hurt.” Thanos shifted his eyes down to the cauterized stab wound in his side. “You’ve taken care of that wound well, but I do have a means of making sure it heals faster. But first, you’re in need of sustenance. I won’t be long.”

He patted the cage before turning away.

“Where are you going? HEY?”

He tried shaking the bars, but it did him no good. Thanos didn’t turn around once as he lumbered out of sight around a corner. Tony stared ahead, seeing the bars, seeing his new prison. He was seething as it all came crashing into him, but then he was slumping against the back of the cage. Maybe it was well deserved. He had failed afterall, so what better place for him was there than jail?

He pulled his knees up to his chest and let the weight of the pain sink in once more.

“I’m sorry Pep,” he muttered. “I’m sorry…everyone.”

The bad blood that had developed between him and half of the team was meaningless now. Strangers and possible future Avengers he would never meet had had their lives snuffed out prematurely. It wasn’t fair. It wasn’t fair that nothing he’d done had been good enough. It wasn’t fair that Thanos got to live and do as he pleased. He shivered as he thought further. It wasn’t even fair that he got to live. But was this really living?

Tony shut his eyes and let his body sink further until he fell into a sleepless nap.

 

Heavy footfalls roused him to wakefulness. He opened his bleary eyes and saw the giant coming toward him with what looked like a bota bag in his hands. Tony pressed himself against the back of the cage. Thanos found it amusing as he softly chuckled.

“I hope the wait hasn’t been too dreadful.”

Tony simply glared up at him as he hovered over the cage. He looked at the bag and it was then that his stomach actually growled. It had been ages since he’d eaten, but no matter what, he was determined not to let a drop of whatever was in that bag into his belly.

“Now would be a good time to tell me if you must relieve yourself.”

At that, Tony wrinkled up his nose. He didn’t even want to think about how restroom breaks would work if his new home was to be the cage. It was only as roomy as a king size bed.

“The only place I’m shitting myself is on your lap.”

Again Thanos chuckled, then he reached for the lock. Tony felt his heart leap. Thanos of course, noticed.

“Do I need to remind you of how helpless you are?” he warned.

No he didn’t need reminding, but Tony wasn’t quite ready to back down. He simply glared at the bag.

“I’m not hungry,” he replied stubbornly. “So you can get that shit away from me.”

“No point in lying to me Tony. I know you’re starved.”

The top of the cage was pulled back. The small bit of hope and fight Tony had summoned, was crushed as the beast hovered over him. He felt so small in comparison that he tried to shrink in on himself as if it would somehow protect him. It didn’t make things difficult for Thanos as he simply reached down and pulled him into his arms again. He crossed over to the old throne and settled himself upon it like a king. At the same time, he maneuvered Tony so that he was cradled across his lap like a baby.

Tony’s cheeks flushed as he watched Thanos position the bag as though he was about to bottle feed him. He hadn’t made the connection beforehand. 

“I’m human,” he piped up. This wasn’t his world afterall, which naturally meant a foreign planet’s diet would not work in his system.

“I’m well aware,”Thanos said as he brought the nipple like end toward his lips. “You’ll be able to consume this just fine.”

“No! I don’t-”

The tip was suddenly shoved into his mouth. Tony gaged and tried to push it back out, but Thanos kept it in place as he tightened his grip around his body. The next sensation to hit was something creamy and thick hitting his tongue. He gagged even more as he attempted to spit it back out around the nipple, but the creamy substance was coming in so fast, he was forced to swallow. It had a faint vanilla taste mixed with something else he couldn’t detect that was slightly tart. He didn’t care for it. He squirmed hard in the monster’s grasp. Another attempt to spit it up resulted in him choking, and it was then that Thanos removed the tip. The white substance ran down his chin as he coughed. 

Thanos sat him up just a bit so he could rub his back to relieve him.

“Easy now, easy. You consumed a little too much.”

Tony took the chance to spit out as much as he could, but unfortunately enough of it had made it down. 

“Bastard…what…what is that crap?”

“Nutrition,” he answered simply. Thanos started moving the tip back into place once his coughing stopped. Tony was quick to put up a hand to stop him. “Tony, now is not the time to be difficult. Do you want to starve?”

“I’d rather starve than swallow that crap,” he growled. Where was a good cheeseburger when he needed one?

“Nonsense.”

The nozzle was shoved back in, and Tony was forced to start guzzling it down. There was a look of satisfaction present on the titan’s face, while Tony kept his nose and eyes scrunched up from the odd taste. He hated the way it quickly coated his throat, and the fact that it was slightly warm didn’t help. 

“You’ll come to appreciate it. Trust me.”

But Tony wouldn’t. He would never adapt to whatever Thanos had in mind, nor would he adapt to the taste of his creamy nutrition. His eyes watered a bit as he stared back at Thanos, hoping he would see that he was begging him to stop, but either Thanos didn’t get the message, or he didn’t care. 

“The things you consumed on your planet,” he started, “won’t compare to what I can give you. Trust me Tony, you’re quite lucky to be where you are.”

Tony wished he could argue that he wasn’t lucky. He was damned in the worst way possible. He squirmed uncomfortably as the cream was starting to fill him up. The heaviness of it wasn’t something he was used to, and it made him wonder if this ‘nutrition’ would fatten him up. 

A few times he attempted to block it going down by throwing his tongue up, but it created gag problems, and the substance was able to slip past it anyways. Tears ran down his eyes. For a minute he thought of Peter and the rest of the team. How would they have reacted if they were able to see their enemy bottle feeding him? Maybe they would have thought it was fitting of the great Tony Stark who was actually about as weak as a poor baby.

He shut his eyes and tried to tune it out. It was easier to just concentrate on not coughing since Thanos refused to let up anytime soon. Little by little, his stomach was getting fuller. 

When his eyes began to droop and the bota bag lightened, Thanos pulled it away. He shook it and smiled.

“That’s my good pet,” he praised.

Apparently Tony had practically consumed the whole thing, but by now he was so full he barely cared. As much as he hated to admit it, the “nutrition” was filling enough to satisfy his earlier hunger. It was as if he’d eaten a meal and not drank something akin to a thick milkshake. He looked at Thanos, still finding it hard to believe that the bastard had just fed him; that he had gone so far to take care of his needs in the most bizarre and unsettling way.

Thanos ran his fingers over his hair and leaned back further into the throne. 

“It’s going to be an adjustment for you. I get that. But you will. You will see Tony, that I know what’s best. I know what’s best for you, pet.”

One of his thumbs moved to wipe away excess cream from his chin. 

“This was not supposed to happen,” Tony declared, though it came out weak.

Thanos just smiled widely.

“I think it was.”

Tony couldn’t argue against it anymore. The food was starting to make him slip into a comforting daze. He couldn’t be sure if he had been drugged or if it was just the simple after effect of having eaten too much. Either way, he had no fight left in him, so he allowed himself to doze in his arms.


	4. Chapter 4

Time was starting to pass now, and Tony found his days weren’t so different from his first. 

He spent much of his time in the cage. At one point Thanos had given him a cushion to lie on when sleeping, and it had been quite comforting. In the mornings, the day started with the beast pulling him from his prison for breakfast through a bag. Eating like a baby, all cradled in Thanos’s arms, was still something he couldn’t get used to, and the same went for the creamy “nutrition”. God he was missing eggs and bacon.  
If it wasn’t bath day, Thanos would walk the gardens. As his pet, Tony wasn’t allowed to walk as Thanos was determined to carry him everywhere. Tony was sure it was because he feared he’d run off, which he would. Then again, the planet was still foreign to him, and he wasn’t sure how dangerous it could be if he was on his own. If anything he was just grateful he wasn’t forced to have a collar and leash.

Sometimes Thanos would just sit and watch the skies. Tony was made to sit on his lap at such moments. There were days when he tried to squirm free, and others where he just sat quietly as Thanos told stories of his past. One of his large hands always locked across his belly, making escape impossible.

At the end of the day, he was returned to his cage. Thanos would smile at him and wish him a good night’s rest before departing to whatever chamber he used for sleeping in the damaged habitat. But that was starting to change as Thanos began putting his effort into putting their palace like home back together. Watching Thanos reset beams and fill the holes in the ceiling was the only form of entertainment Tony had. When he wasn’t watching, he was thinking.

It was hard for him not to think of the others, particularly when he didn’t want to feel the pain at the moment. He would see Peter, popping off pop cultural references to express an idea. Tony figured if they had made it back home, they would have worked on some missions together; Iron man and Spiderman working side by side. It would have been a way to rebuild the loss that had occurred when the team had broken apart.

On that note, Steve came to mind. He didn’t think it was impossible for them not to move past hard feelings. Thanos was a being that required differences be put aside for the sake of humanity. They would have had to work together then, but after that he doubted their friendship would have returned to the way it was. Now that he was Thanos’s pet, he actually longed to make that phone call to him. 

Whenever Pepper drifted to the forefront of his mind, his eyes would become blurry with tears. The wedding that had been put off until recently, was completely over now. He still wasn’t certain if she had been one of the unfortunate ones to go, but as more days passed he leaned on the idea that she had vanished into dust just like Peter, and Strange, and Quill and his people. He was not with her any anymore; he was with Thanos.

“My pet.”

Tony looked past the bars as Thanos greeted him while approaching. The billionaire only gave him a tired glare. He looked away from the beast to show, as he always did, that he wasn’t interested in being friendly; that was, unless it resulted in a spanking.

“I’ve got something special to give you.”

“Whatever it is, you can shove it right up your purple ass,” Tony snapped. 

The titan made a noise like he was amused. It always pissed Tony off to know that he didn’t take any of his threats or insults seriously. They were just jokes. 

“Well, it’s funny you should mention that particular part of the body.”

The way he’d said it caught Tony’s attention. He tensed and pressed against the back of the cage as panic started to set in. 

“No,” he cried as he started shaking his head. “I didn’t do anything. I wasn’t…I wasn’t bad.”

Thanos cocked his head as he began drumming his fingers on the top of the cage.

“What’s gotten into you my pet?”

Tony just shook his head. 

“I don’t…I don’t need a spanking. I didn’t do anything wrong.”

The titan’s brows raised as he realized what Tony must have thought. 

“Oh no, you misunderstand Tony. I’m not giving you a spanking.”

“Then, what did you mean?”

Thanos just smiled and pried open the cage’s top. Tony shrunk down, but other than that, didn’t try anything to stop the Goliath from reaching down and scooping him up. It still wasn’t something he’d gotten used to, particularly since in all the time he’d been with the beast he was still denied clothes. As disturbing as it was, he did feel he was getting used to being naked little by little as the days passed. Thanos pressed Tony against his chest and held him there with one hand. With the other, he reached into a pocket and produced a shining silver stone. Tony stared at it and was immediately reminded of the moment he’d lost everything. It wasn’t an infinity stone, but regardless it wasn’t a welcomed sight.

“What the hell are you gonna do with that?” 

Thanos didn’t answer in the way that he hoped.

“This may sting a little.”

With the stone secured in the palm of his enormous hand, Thanos clamped it down upon Tony’s tailbone. In an instant, the stone began to burn causing Tony to howl and squirm. Thanos tightened his grip as his kicking started up.

“Ssshh…ssshhh, it’s almost over,” Thanos said gently.

Tony wanted it over now.

“STOP IT!” 

Tony struggled harder as he felt a sensation of the stone sinking into his flesh. It seemed to be striking against his very tailbone, in a very unpleasant way. He couldn’t make sense of what was happening.

“What the hell…are you doing to me!”

“Easy now, we’re almost there pet.”

The burning pain was indeed dying down, but that didn’t mean Tony felt any better about it. He grounded himself into the titan’s shoulder as a desperate means to escape the inescapable. When Thanos removed his hand, there was mild warmth above his rear, along with a funny tingling sensation.

“There now,” Thanos said happily.

“There, wha…”

The tingling grew until he felt the oddest sensation of something growing just above his ass. It wasn’t fully painless, which was why Tony clung to Thanos, sobbing. Thanos ran his fingers gently over his hair in a soothing manner as he gently rocked him.

“What’s, happening?” Tony cried as tears streamed down his face as the strange pressure continued.

“There there my pet. You’ll be alright in a moment.”

A moment came soon enough as the growing stopped. Tony blinked back tears as his mind tried to figure out what had just happened. 

“There now,” said Thanos in a pleased manner. “That wasn’t so hard was it?”

“What did you do, just now?” He felt something touch against the back of his leg. Knowing it couldn’t have been Thanos, he jumped. Something wasn’t right. He could feel it with the slight wiggle of his hips.  
In response, the titan set him down on his feet, and after much hesitation, Tony turned and dropped his eyes down to his rear. What he saw had him scrambling away, though there was no running from what he saw.

Right above his rear, like an animal, was a long, smooth, flesh colored tail. It appeared to be a little over three feet and looked thick like a monkey’s. Without meaning to, he somehow caused the tip of the tail to curl. Tony jumped in surprise. 

“What the hell?”

He forced himself to calm so he could do it again, and this time he was able to make it sway. It didn’t require a ton of concentration to move the tail. It was as easy as moving an arm.

“Beautiful isn’t it,” Thanos praised.

Tony bared his teeth. He was on him instantly with fists swinging into the alien’s thick flesh.

“You call giving me a tail beautiful bastard?”

Thanos easily held Tony off. The tail moved wildly due to his sudden rage.

“Would you prefer a different type of tail?”

“Fuck you! I don’t want any kind of tail! Why the hell did you give me a tail?!”

“Tony calm yourself.”

“Take it off! TAKE IT OFF!”

Thanos let the human continue his outburst a minute longer before grabbing his swinging fists to stop the attack. He stared hard at Tony who was shivering and breathing quite hard.

“Why?” he finally asked in a shaky breath.

Thanos observed him closely before answering.

“I believe you deserved a nice reward for behaving so well lately.”

Tony wasn’t fooled. If there was any truth to it, it wasn’t the whole truth. He was a pet now, an animal, which meant that it was better to fully embrace the part with the one thing most animals had on their bodies. On top of that, it would further disassociate him from his old species. Humans, afterall, did not have tails. He had a tail now, which meant that he clearly was no longer human.  
With a heavy sob, he dropped his head and fell to his knees. The tail curled around him almost like a comfortable blanket.

**Notes for the Chapter:**

> I liked the idea of creating a twist on the thanos/Tony plot with Thanos giving Tony a tail to make him more pet like.


	5. Chapter 5

It was a prehensile tail. Tony quickly found out when he decided to experiment with its movements when trapped in the cage. He could use it to grab the bars or tickle the lock of the cage, but it did nothing to free him. Still, it was like an extra arm. When he got too bored, he imagined himself in the lab using the tail as an extra hand to place tools into his hands or hold a piece of the suit in place. 

It had come to the point where Thanos was willing to give him a little more freedom than usual which meant that he didn’t have to stay trapped behind bars at all times. When that happened, he found himself wandering through the garden. The intense colors and the greatness of the flora was a superior sight than what could be found on earth.

Tony walked along a marked stone path and took it all in. The air was still enriching and tended to revive his spirits, particularly when they got too low. He paused against a tree and just looked at his environment. Large stones and columns littered the garden, creating a sense of some great history. 

Wanting to take a look at it from a different position, he glanced up at the tree. The branch wasn’t too high, and so a smile lifted the corners of his lips. He leaned forward and directed his tail to latch onto the branch and curl around it. There was great power in that appendage since he was able to actually hang from it like an opossum in a cartoon. Though seeing the world upside down didn’t exactly make for a great way to view it, he found he felt a little comfortable taking it in that way, at least for a little while.

He released a deep breath, then quietly shut his eyes.

“Having fun pet?”

He opened them and saw Thanos standing before him, upside down of course. 

Tony reached up and pulled himself up onto the branch to better take him in. He gave a nod which made Thanos smile. The titan easily reached up and petted his head. In the past he had fought against it, but now it had become soothing. There were a few days where he didn’t exactly like it, but all in all it wasn’t too bad. 

“I was on my way to the cliffs. I figured you’d like to join me.”

Thanos lowered his arm, and without putting up a fuss, Tony clung to it. Thanos pulled him against his chest like he’d done so many times before. Tony didn’t find it humiliating as he once had long ago. It had taken time of course to get to this point of comfort. Tony was never sure how much time it had taken. As far as he knew, he had spent at least a year and a half with Thanos. The struggle he’d undergone when first discovering what his new life would be was behind him. The world had moved forward while he had remained behind, becoming something he never thought he would.

Tony didn’t like to think on it. In fact, it was easier just to sink into what was right in front of him. Of course there had been a few times when he imagined finding a way to escape, but Thanos had never been careless enough to provide him with a means of leaving. 

“I think you’ll like where I’m taking you pet.” 

Tony felt no reason not to trust his word. It was a mark of how far they’d come. He settled against his shoulder as the scenery passed by. The wind blew softly against his bare back, but it felt nice. The wind added with the heat of the sun felt soothing, so much so that his tail began to sway gently back and forth.

Past tall trees and up a rocky trail eventually brought Thanos to the cliffs. When Thanos came to a stop, Tony’s eyes opened. Apparently he had dozed off and wasn’t fully aware of doing so.

“Look my pet.”

Tony raised himself up and took in the environment on a higher plane. His mouth parted just slightly as he noticed golden mountains rising in the background and a sea of various shades of greens from the field below. It was nature at its finest.

“It’s beautiful,” Tony noted, making the titan hum in agreement.

“This is the ideal spot for watching a sunset,” Thanos explained. 

“Sunset,” Tony muttered quietly.

Thanos looked down at him curiously, then lowered him to the ground. 

“Tell me Tony, do you ever think about your old home?”

Tony looked up at him with a quirked brow. It certainly wasn’t a question he ever expected to hear from him. Sure he’d had moments where he had thought of home; of his old teammates, and friends. Even Pepper had passed before his eyes once. But by now, such images were starting to fade. What was home anymore after a year and a half spent with a creature he’d come to view as his owner? What was he? Who was he?

“I…I…” He couldn’t confess it. The thought of the past was unsettling now.

He curled in on himself and started to shiver as the memories twisted in his mind like a bad dream. Thanos reached down and scooped him into his arms again.

“My dear pet, I didn’t mean to upset you.” His hand moved in a slow circle upon his back. “I was merely curious. I’m sure you’d rather not be plagued with memories of that old life. But don’t worry. In time, you’ll completely forget about it. You’ve moved on, and life has been good for you here hasn’t it?”

Tony let the question weigh in his mind before giving a slight nod. Sometimes it wasn’t good, but for the most part it hadn’t been horrible.

“And I’ve taken good care of you haven’t I?”

“Yes,” he agreed.

He patted his head, and Tony relaxed enough to lay it upon his shoulder. 

“Good. Let’s not dwell on the past. Not when we have such beauty before us.”

Tony took it the view once more and put aside the past. Never in a million years would he have seen such a life coming for him, and since it had, he supposed this was how it was always meant to be. 

He released a sigh and curled his tail around himself.

**Notes for the Chapter:**

> I'm happy to have come across Thanos/Tony fics since it inspired this odd little fic. Anyways, glad you enjoyed :)  
> I hope it inspires some odd Thanos/Tony fics. This pairing has become quite interesting to me.

**Author's Note:**

> This was meant to be a one-shot, but it seemed easier to stretch this out a little bit further, slightly. I'm not at all well versed on Thanos since I've only encountered him in the movie, so he may have capabilities that aren't canon, or perhaps an infinity stone will be used. We'll see.


End file.
